• Journal of Korea Water Resources Association
• /
• v.35 no.2
• /
• pp.231-240
• /
• 2002

The wetland has very important functions in hydrologic and ecological aspects and the research of wetland functions requires the basic hydrological properties such as water quantity. However, we do not have a research work on the hydrological properties for a wetland study in Korea. Therefore, this study is to estimate the relations between the volume(V), the area(A), and the depth(h) of water in the wetland which might be the basis for the wetland research in Korea. To estimate the relations, we derive the basic equations, obtain the surveyed data and do modelling, and estimate the relations of A-h and V-h using the Surfer program. The estimated and observed volumes for 5-wetland are compared and the errors are in the range of 2 % to 11 % for 4-wetland and 34 % for the rest. The wetlands in small errors showed the similar ones with the profile of the wetted perimeter which is assumed for the derivation of the equation but the wetland of large error has much different profile with the assumed one. We re-estimate the volumes for 3-wetland(W3, W4, W5) which showed the large errors due to the bended profiles of the wetland slopes. say, after the slopes was divided into two parts of upper and lower ones, the volumes were estimated. From our re-estimation, we obtained very good results ranged from 1 % to 8 % in their errors. We conjecture that the procedure suggested in this study might be useful as a reference for the future research on the relations of V-A-h in Korea.

• Korean Journal of Radiology
• /
• v.23 no.10
• /
• pp.959-975
• /
• 2022

Objective: To investigate the agreement and reliability of estimating the volumes and normative percentiles (N%) of segmented brain regions among NeuroQuant (NQ), DeepBrain (DB), and FreeSurfer (FS) software programs, focusing on the comparison between NQ and DB. Materials and Methods: Three-dimensional T1-weighted images of 145 participants (48 healthy participants, 50 patients with mild cognitive impairment, and 47 patients with Alzheimer's disease) from a single medical center (SMC) dataset and 130 participants from the Alzheimer's Disease Neuroimaging Initiative (ADNI) dataset were included in this retrospective study. All images were analyzed with DB, NQ, and FS software to obtain volume estimates and N% of various segmented brain regions. We used Bland-Altman analysis, repeated measures ANOVA, reproducibility coefficient, effect size, and intraclass correlation coefficient (ICC) to evaluate inter-method agreement and reliability. Results: Among the three software programs, the Bland-Altman plot showed a substantial bias, the ICC showed a broad range of reliability (0.004-0.97), and repeated-measures ANOVA revealed significant mean volume differences in all brain regions. Similarly, the volume differences of the three software programs had large effect sizes in most regions (0.73-5.51). The effect size was largest in the pallidum in both datasets and smallest in the thalamus and cerebral white matter in the SMC and ADNI datasets, respectively. N% of NQ and DB showed an unacceptably broad Bland-Altman limit of agreement in all brain regions and a very wide range of ICC values (-0.142-0.844) in most brain regions. Conclusion: NQ and DB showed significant differences in the measured volume and N%, with limited agreement and reliability for most brain regions. Therefore, users should be aware of the lack of interchangeability between these software programs when they are applied in clinical practice.

• Computational Structural Engineering
• /
• v.9 no.4
• /
• pp.135-140
• /
• 1996

Single angle or channel with thin-walled open section can be used as compression member for example as web member in truss. In this case the inevitable eccentricity due to fabrication is commonly neglected in structural design. However eccentricity effect should be considered in the member design, especially in case of compression member. The critical loads of compression members that buckle by twisting or by a combination of bending and twisting are to be determined by solving governing differential equations. In this paper, the investigations are limited to the rolled channels([), equal-leg angles(L), lipped channels(C) and the applied loads are assumed to have some eccentricities.

• Proceedings of the KIPE Conference
• /
• 2004.07b
• /
• pp.992-996
• /
• 2004

Small electric motors in an automobile perform various tasks such as engine cooling, pumping, and in heating, ventilating, and air-conditioning (HVAC) system. At present, most of dc motors are supplied by 12V or 24V batteries. However, DC motors surfer from lack of efficiency, low life cycles and unreliability. Therefore, there is a growing interest in substituting DC motors for advanced AC motors including switched reluctance motors. Although there are several other forms SRM converters, they are either unsatisfactory to the control performance or unsuitable for the 12V-battery powered 3-phase SRM drives. Taking into account the requirement for effective operation and simplicity structure of converter in the limited internal environment of automobiles, the author inclines toward selecting the modified C-dump converter as well as the energy efficient C-dump converter. This is so that more economical and efficient converter topology in automobile industries can be utilized. This paper describes the foundation for the design and development of a 12V-250W-3000rpm SRM drives for automobiles. Furthermore, complete circuit, computer simulation and experiment results are presented to verify the performance of the C-dump converters.

• Bulletin of the Korean Chemical Society
• /
• v.29 no.9
• /
• pp.1755-1760
• /
• 2008

Energy minimization and conformational studies of molecular ions generated by ESI (electrospray ionization) tandem mass spectrometry (MS/MS) can be used for the discrimination of stereoisomeric permethylated and sodium cationized trisaccharides. Sets of fucose-containing trisaccharides having different internal and terminal linkages have been synthesized to analyze the reducing terminal linkage positions using BT and IT fusion approaches. A detailed investigation has been undertaken on the conformational behaviors of four trisaccharide fragments from human milk and blood group determinants of Type 1 and Type 2, namely Fuc($\alpha$1- 3)Gal($\beta$1-3)GalNAc and Fuc($\alpha$1-3)Gal($\beta$1-X)GlcNAc where X = 3, 4 and 6 using molecular modeling methods. Three dimensional rigid and adiabatic phi-psi-energy maps (Surfer program) describing the energy as a function of rotation around corresponding glycosidic linkages were calculated by SYBYL molecular modeling and MM4 force field programs conjunction with cleavage energies of ESI MS/MS for the side group orientations. This approach predicted conformational behaviors exhibited by isomer saccharides for future applications on biologically active glycoconjugates and to exploit a faster method of synthesizing a series of structural isomeric oligosaccharides.

• Speech Sciences
• /
• v.13 no.3
• /
• pp.67-82
• /
• 2006

The purpose of this experimental study is to investigate formant characteristics of Korean monophthongs spoken by Japanese learners and to compare the characteristics of vowels produced by the Japanese learners with those of the Korean native speakers. The data consisted of three categories: eight vowels in isolation, words including eight vowels in carrier sentences, and words including eight vowels in natural sentences. In this study, formant frequencies of the vowels were measured by Wave Surfer. It was assumed that the formant frequencies of the Korean vowels produced by the Japanese learners could be different from those of the Korean native speakers due to the influence of their own Japanese vowels. Results of this study showed that the Japanese learners had the difficulties to distinguish between the pairs /-/and /ㅜ/, /ㅓ/and /ㅗ/, and /ㅏ/and /ㅔ/. In Japanese vowels, F2 frequency value of /ㅜ/ was similar to that of the Korean /-/. It means that when the Japanese leaners produced Korean /ㅜ/, they might neutralize /-/ and /ㅜ/. Besides, there were not /ㅓ/and /ㅐ/ in Japanese vowels. Therefore, they tended to pronounce /ㅓ/ similar to /ㅗ/ which has the most similar formant frequency value with that of /ㅓ/, and /ㅐ/ was pronounced similar to /ㅔ/ for the same reason.

• Journal of the Korean Home Economics Association
• /
• v.42 no.3
• /
• pp.195-209
• /
• 2004

The purpose of this study was 1) to examine the usage of mobile internet by cell phone or palm pilot, etc., 2) to analyze mobile users' lifestyles, 3) to examine preferred fashion services according to users' lifestyles and 4) to investigate service satisfaction and preference with the mobile internet. 193 university students in Seoul were randomly selected as subject. The data was analyzed using descriptive statistics (i.e., percentage, frequency), factor analysis, cluster analysis and ANOVA. The results of the study were as follows: first, most mobile users spent 10 min a day for using the mobile internet (i.e., short message service) mainly in transportation vehicles. Secondly, five factors in the mobile users' lifestyle were named as: 'surfer', 'absorber', 'expert', 'accepter' and 'enthusiast'. Thirdly, two factors in the preferences of fashion service on mobile internet were 'customized information service' and 'ordinary information service'. Fourthly, according to the internet lifestyle, mobile users were classified into three groups: 'mania group', 'follower group', and 'veteran group'. The mania group was the highest group in mobile service satisfaction and service preference. Marketing implications are discussed for the successful mobile business in clothing and textile industry.

• Korean Journal of Biological Psychiatry
• /
• v.24 no.4
• /
• pp.225-234
• /
• 2017

Objectives Local gyrification reflects the early neural development of cortical connectivity, and is regarded as a potential neural endophenotype in psychiatric disorders. Several studies have suggested altered local gyrification in patients with bipolar I disorder (BD-I). The purpose of the present study was to investigate the alterations in the cortical gyrification of whole brain cortices in patients with BD-I. Methods Twenty-two patients with BD-I and age and sex-matched 22 healthy controls (HC) were included in this study. All participants underwent T1-weighted structural magnetic resonance imaging (MRI). The local gyrification index (LGI) of 66 cortical regions were analyzed using the FreeSurfer (Athinoula A. Martinos Center for Biomedical Imaging). One-way analysis of covariance (ANCOVA) was used to analyze the difference of LGI values between two groups adjusting for age and sex as covariates. Results The patients with BD-I showed significant hypogyria in the left pars opercularis (uncorrected-p = 0.049), the left rostral anterior cingulate gyrus (uncorrected-p = 0.012), the left caudal anterior cingulate gyrus (uncorrected-p = 0.033). However, these findings were not significant after applying the multiple comparison correction. Severity or duration of illness were not significantly correlated with LGI in the patients with BD-I. Conclusions Our results of lower LGI in the anterior cingulate cortex and the ventrolateral prefrontal cortex in the BD-I group implicate that altered cortical gyrification in neural circuits involved in emotion-processing may contribute to pathophysiology of BD-I.

• Journal of the Korea Fashion and Costume Design Association
• /
• v.7 no.2
• /
• pp.159-170
• /
• 2005

In this paper we examine the patterns of the subcultural fashion styles in the 20th century in terms of various subcultures in the period. First, we define the concept of the subcultural fashion styles and in turn, examine the subcultural fashion styles from 1950s to 1990s while focusing on the way each generation resisted against the mainstream through its styles. The subcultural fashion styles examined and analyzed in this study are mainly British and American styles. some of European and Western Indian styles are also included. In this paper, a subcultural fashion style is understood as a way of deviate or resistant expression within a society. It differentiates itself from the main style by deliberately and publicly asserting its own identity. And as a result, it is realized in a form of a fashion with its repressed subconsciousness, with resistance to the alienation from the society, and with deviation from the normative ethics and the morality of a society. In conclusion, we classify the subcultural fashion styles into two patterns based on their form of resistance which tries to distance itself from the ritual code of the day: the dressing of the escape from time and the dressing of the escape from space. The first pattern is characterized by nostalgia or futurism, and includes psychedelic, rastafarian, raver, techno style. The second Pattern includes surfer, folky, hippy, new age traveller, cyberpunk style. Especially, an emphasis is given on ethnicity, naturalism, or a closed space within a city in dressing of the escape from space.

• Journal of KIISE:Computing Practices and Letters
• /
• v.16 no.1
• /
• pp.100-104
• /
• 2010

In the past decade, various search engines have been developed to retrieve web pages that web surfers want to find from world wide web. In search engines, one of the most important functions is to evaluate and rank web pages for a given web surfer query. The prior algorithms using hyperlink information like PageRank incur the problem of 'topic drift'. To solve the problem, relevance propagation models have been proposed. However, these models suffer from serious performance degradation, and thus cannot be employed in real search engines. In this paper, we propose a new ranking algorithm that alleviates the topic drift problem and also provides efficient performance. Through a variety of experiments, we verify the superiority of the proposed algorithm over prior ones.